摘要
为了研究激光辐照材料引起表面波纹现象及原因,采用钕玻璃激光器产生的脉冲激光来冲击黑漆作为吸收层的AZ91镁合金试样。激光冲击后采用表面三维轮廓仪对试样冲击区域表面进行测量,结果得到在冲击区域存在波纹分布现象;观测并描绘了表面形貌及表面波纹的分布情况,并分析了材料表面波纹特性与激光能量的关系;得出波纹特性受激光能量影响。最后从等离子体对试样的作用和等离子体内部相干受激光散射机制引起的光栅效应两个方面出发,讨论了热传导、热辐射以及激光照射等因素在试样表面产生热微扰动现象的耦合过程,进而从表面热微扰动的非平衡状态探讨了表面波纹的形成机理。
In order to study the ripple phenomena and its causing mechanism on material surface that caused by the laser irradiation,the pulse generated by neodymium glass laser was used to shock the specimen of magnesium alloy AZ91 covered with black paint as the absorption layer. The three-dimensional surface measurement instrument is applied to measure the shocked region of the specimen surface after shocking. And the ripples phenomenon is observed in the shocked region from the measurement results. The surface morphology,as well as the distribution of the surface ripples,is observed and described; and the relation between the characteristics of the ripples and the laser energy is analyzed. It can be concluded that the characteristics of the ripples are affected by laser energy. Based on the effects of the plasma to the specimen and the grating effects caused by the mechanism of coherent stimulated light scattering within plasma,the process of generating thermal micro-disturbance on the sample surface by coupling the thermal conductivity,the thermal radiation and the laser irradiation is discussed,and then the formation mechanism of the surface ripples caused by the non-equilibrium state of the surface thermal micro-disturbance is discussed.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2010年第9期2613-2619,共7页
Acta Optica Sinica
基金
国家自然科学基金(50735001)
江苏省高校自然科学基金(09KJB460002)资助课题
